Hi Kenny! Just an observation but from the photos is appears that the areas of conformal coating delamination are from some material which is "seeping out" of the vias. Have you investigated to see if either cleaning step is leaving solution trapped in the via holes? Dave Hillman Rockwell Collins [log in to unmask] "Bloomquist, Ken" <Ken.Bloomquist@A STRONICS.COM> To Sent by: TechNet [log in to unmask] <[log in to unmask]> cc Subject 04/06/2007 09:29 [TN] Conformal Coat Dewetting AM Please respond to TechNet E-Mail Forum <[log in to unmask]> ; Please respond to "Bloomquist, Ken" <Ken.Bloomquist@A STRONICS.COM> Good afternoon all, I've go some assemblies that are not taking conformal coating in some areas. The boards are reflowed and then selective wave soldered with a pallet. They us a water sol flux and run it through an inline wash using DI. We wash them in a batch washer using a mild saponifier prior to coating. The boards are cleanliness tested in a ROSE tester and then coated with polyurethane. It is only on a few boards and it appears to almost be coming from the via's. If we try to brush coat over it it still won't coat. If we clean it with IPA then it coats just fine. We've ruled out silicone and finger grease. I have a couple of photos so you can see what it looks like. One is black light showing the void areas. The other one is where we tried to touch up the coating around a via and you can see how it pulled back. http://www.ema-wa.com/DSCF0845ViaContamAreas.jpg http://www.ema-wa.com/DSCF0840_Via_Close-up_Y1_WL.JPG Thanks, KennyB --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------